BackPressureBarrier

simple module

This module prevents backpressure propagation from its output to its input and vice verse. It always allows pushing and pulling packets independently of what the connected modules would allow to do in their current state. Both pushed and pulled packets pass through unchanged, but the operations may raise a runtime error due to this module preventing backpressure propagation.

Inheritance diagram

The following diagram shows inheritance relationships for this type. Unresolved types are missing from the diagram.

Used in compound modules

Name	Type	Description
Ieee8021qFilter	compound module	This module implements the IEEE 802.1Q per-stream filtering and policing. The relationship between streams, gates and meters is not one-to-one. The number of streams, gates and meters can be different and the module will take care about the connections between the submodules based on the streamFilterTable parameter.
SimpleIeee8021qFilter	compound module	This module implements a simplified version of the IEEE 802.1Q per-stream filtering and policing. Each filtered stream has its own path where metering and filtering happens independently of any other stream.

Extends

Name	Type	Description
PacketFlowBase	simple module	This is a base module for various packet flow modules. A packet flow module passes or streams all pushed or pulled packets after processing them from its input to its output.

Parameters

Name	Type	Default value	Description
displayStringTextFormat	string	"passed %p pk (%l)"	determines the text that is written on top of the submodule

Properties

Name	Value	Description
display	i=block/segm
class	BackPressureBarrier

Gates

Name	Direction	Size	Description
in	input
out	output

Signals

Name	Type	Unit
packetPushedIn	inet::Packet
packetPulledIn	inet::Packet
packetPushedOut	inet::Packet
packetPulledOut	inet::Packet

Statistics

Name	Title	Source	Record	Unit	Interpolation Mode
flowIncomingDataRate	flow specific incoming data rate	throughput(demuxFlow(merge(packetPushedIn, packetPulledIn)))	vector	bps	linear
outgoingDataRate	outgoing data rate	throughput(merge(packetPushedOut, packetPulledOut))	vector	bps	linear
incomingDataRate	incoming data rate	throughput(merge(packetPushedIn, packetPulledIn))	vector	bps	linear
outgoingPacketLengths	outgoing packet lengths	packetLength(merge(packetPushedOut, packetPulledOut))	sum, histogram, vector	b	none
flowIncomingPacketLengths	flow specific incoming packet lengths	packetLength(demuxFlow(merge(packetPushedIn, packetPulledIn)))	sum, histogram, vector	b	none
flowOutgoingDataRate	flow specific outgoing data rate	throughput(demuxFlow(merge(packetPushedOut, packetPulledOut)))	vector	bps	linear
incomingPacketLengths	incoming packet lengths	packetLength(merge(packetPushedIn, packetPulledIn))	sum, histogram, vector	b	none
flowOutgoingPacketLengths	flow specific outgoing packet lengths	packetLength(demuxFlow(merge(packetPushedOut, packetPulledOut)))	sum, histogram, vector	b	none
incomingPackets	incoming packets	merge(packetPushedIn, packetPulledIn)	count	pk
outgoingPackets	outgoing packets	merge(packetPushedOut, packetPulledOut)	count	pk

Direct method calls (observed)

call to	function	info
MessageDispatcher	inet::MessageDispatcher::pushPacket	pushPacket
PacketMultiplexer	inet::queueing::PacketMultiplexer::handleCanPushPacketChanged	handleCanPushPacketChanged
PassivePacketSink	inet::queueing::PassivePacketSink::pushPacket	pushPacket

Called methods (observed)

function	info	call from
inet::queueing::BackPressureBarrier::handleCanPushPacketChanged	handleCanPushPacketChanged	PassivePacketSink
inet::queueing::BackPressureBarrier::pushPacket	pushPacket	PacketMultiplexer

Pushed in messages (observed)

gate	msg	kind	ctrl	srcModule	tags
in	Packet	0		PacketMultiplexer	DirectionTag, PacketProtocolTag, DispatchProtocolReq?, DropEligibleInd?, EligibilityTimeTag?, EncapsulationProtocolInd?, InterfaceInd?, LabelsTag?, MacAddressInd?, PcpInd?, RateTag?, StreamInd?, StreamReq?, UserPriorityInd?, VlanInd?

Push out messages (observed)

gate	msg	kind	ctrl	destModule	tags
out	Packet	0		MessageDispatcher	DirectionTag, DispatchProtocolReq, DropEligibleInd, EncapsulationProtocolInd, InterfaceInd, MacAddressInd, PacketProtocolTag, PcpInd, StreamInd, UserPriorityInd, VlanInd, EligibilityTimeTag?, LabelsTag?, RateTag?
out	Packet	0		PassivePacketSink	DirectionTag, LabelsTag, PacketProtocolTag, StreamReq

Region Tagging operations (observed)

tagType	tagAction
FlowTag	mapAllTags

Source code

//
// This module prevents backpressure propagation from its output to its input
// and vice verse. It always allows pushing and pulling packets independently
// of what the connected modules would allow to do in their current state. Both
// pushed and pulled packets pass through unchanged, but the operations may raise
// a runtime error due to this module preventing backpressure propagation.
//
simple BackPressureBarrier extends PacketFlowBase
{
    parameters:
        displayStringTextFormat = default("passed %p pk (%l)");
        @class(BackPressureBarrier);
        @display("i=block/segm");
}

File: src/inet/queueing/common/BackPressureBarrier.ned